The use of a steel structure enclosed by plastic for improving part strength of components used in transportation vehicle structure is known. Generally, enclosed structures can be used in applications such as cross car members. Typically, a tube such as a hollowed steel tube is used to provide additional structure for the system. The steel tube is inserted in a compression mold and mandrels are inserted into the ends of the tube prior to compression in order to prevent collapse of the tube during the molding process. The mandrels are typically removed during compression and the steel tube remains enclosed by the plastic. This process results in a slower cycle time for molding and a relatively heavy product. It is known that if mandrels are not used the steel tube structure can be crushed or otherwise disadvantageously compressed during injection molding under pressure from at least about 12,000 psi to 20,000 psi.
Therefore, there remains a need in the art to replace the heavy and expensive steel tube with an aluminum extrusion with sufficient cross sectional properties to help prevent collapse with plastic overmold for improving part geometry and strength while minimizing weight, and a process of plastic overmolding of the aluminum extrusion without the use of mandrels.